Drum stuck when tightened 1970 521

[dayuumden]

Hi Community

 

Last night, i finished redoing my brake system on my 521 with new pads, springs, adjusters (rebuilt), cylinders, hoses, drums, and master.

 

I am having a weird issue with the front passenger and I noticed it after I put the wheel on. When I installed the wheel on the truck, it stopped spinning. I thought it was a little weird so i backed out the adjusters all the way and while it spins, it drags a lot and won't spin freely.

 

Tonight I wanted to troubleshoot it so i removed the wheels and once i did that the drum spun freely. At first, I thought my wheels were out of shape and binding it somehow but when I tested it using the lug nuts I noticed that the drum would bind and not spin again.

 

Has anyone encountered this problem that could help me figure out why it's binding?

 

Thank you.

[datsunaholic]

Yes.  I have had several drums where the recess for the wheel is smaller in diameter/deeper than "normal" and some aftermarket wheels won't fit.  They hit the raised edge, pushing the drum (actually bending it) rather than mounting the wheel flat to the face.  I had the exact symptom you have- the drum bound up when the lugs were "tight".  While I was able to temporarily "fix" it with wheel spacers, I ended up searching high and low for drums with the proper sized mounting flange.

[dayuumden]

The odd thing is that it is fine on the other three and even without out the wheel and using just lugs, it would still bind.

[datzenmike]

Try swapping it to another wheel. If the problem swaps with it then it has to be the drum. If the problem stays then something about that wheel is different.

[dayuumden]

I'll try swapping drums. I don't think it's the wheel because it will bind with just lugs.

[dayuumden]

So, I figured it out.... the casing (perhaps a flash) on the wheel cylinder was rubbing up against the drum. Both are new aftermarket so the tolerances and manufacturing isnt the same as OEM. I have included pictures for reference. To fix it, I took a dremel with a stone attachment and grinded it down about a mm or 2. The red arrows show what was causing the bind.

 

I hope this helps for anyone that experiences the same issues.

 

 

 

[banzai510(hainz)]

Brother that good to know!!!!!!!!thanks

 

 

Looks like a new drum also. Maybe its the drum cut different

Is this a chinese drum???????

 

I run the cheap taiwain /italy brake cylinder also, they dont last but had no proplems with them hitting

 

 

Mater cylinder I always have to cut the threaded rod as its to long when engaging the pedal arm

also 521 blled screw not with the wheel clyinder is another issue. with the Y portion

[dayuumden]

Brother that good to know!!!!!!!!thanks

 

 

Looks like a new drum also. Maybe its the drum cut different

Is this a chinese drum???????

 

I run the cheap taiwain /italy brake cylinder also, they dont last but had no proplems with them hitting

 

 

Mater cylinder I always have to cut the threaded rod as its to long when engaging the pedal arm

also 521 blled screw not with the wheel clyinder is another issue. with the Y portion

 

The cylinders are from Dorman, and the drum is from Centric.

 

Where can I find higher quality hardware?

 

The cut on the drum is different than what I had stock on the truck (not sure if it was original or not) and it still rubbed. The inner lip on the old drum was more rounded off. Although on the drivers side it did not rub with the old drum. The aftermarket one had a drag but at first I thought it was the brakes dragging. I also grinded the drivers side down, but not as much.

 

I also installed a Beck/Arnley master and had to cut the thread as well. I learned that from searching Ratsun and finding your post accidentally, thank you!

 

I was able to salvage the factory Y's in the back and one of the fronts. Denmarkboy sent me a replacement for the front passenger.